One of Lakso's earliest writing credits was the 1960 Perry Mason episode "The Case of the Ill-Fated Faker", which guest-starred William Campbell and Kenneth Tobey. Between 1963 and 1966, he wrote or co-wrote over thirty episodes of the drama series Combat! Also during this time, his writing credits included two episodes of 12 O'Clock High, which starred Robert Lansing, and several episodes of the western series Laredo.

Between the late 1960s and late 1970s, Lakso wrote three or more episodes for such television series as Mission: Impossible, The Wild Wild West, The Virginian, The Big Valley, Mannix, The Rockford Files, and Starsky and Hutch (the latter of which starred David Soul). He also wrote an episode of Hawaii Five-O directed by Michael O'Herlihy and guest-starring Sabrina Scharf, an episode of The Six Million Dollar Man which featured Alfred Ryder, and an episode of S.W.A.T. which guest-starred Bert Remsen and Andrew Robinson.

In 1969, Lakso co-wrote the television movie The Pigeon, starring Ricardo Montalban. He wrote several feature films, as well, most notably Paramount Pictures' 1967 family drama Gentle Giant, which starred Clint Howard. He also wrote, directed, and composed the 1974 biographical film 43: The Richard Petty Story.

Later in his career, Lakso was one of the principal writers on all five seasons the action/adventure drama series Charlie's Angels, which ran from 1976 through 1981. He was also a story editor on the show during the first season (1976-77). In 1977, he began directing episodes of the show. In total, he worked on 36 episodes of the show either as a writer, producer, and/or story editor.

Lakso retired in 1986, after writing episodes for The Fall Guy and Airwolf. He died of complications from Parkinson's disease at his home in Beverly Hills, California, on 23 May 2009. He was 76 years old. [1]